Implantable dialysis access port

ABSTRACT

An implantable access port in accordance with one embodiment of the invention comprises a hollow port casing having a first channel, a second channel and a third channel. A self-sealing insert may be disposed within the third channel. The implantable access port may further comprise a graft having a first branch, a second branch, and a third branch, the first branch extending from the first channel and adapted to be anastomosed to a vessel at a first location, the second branch extending from the second channel and adapted to be anastomosed to a vessel in a second location, the third branch extending at least partially into the third channel, wherein the third branch is disposed between the self-sealing insert and the hollow port casing. Methods for performing medical procedures associated with the implantable access port are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Provisional Application No.60/417,204, entitled IMPLANTABLE DIALYSIS ACCESS PORT, filed Oct. 9,2002, the disclosure of which is hereby incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention relates to access ports implantable into a mammalto gain access to veins and arteries thereof. Typically, such ports areimplanted for use during hemodialysis. The access ports of the presentinvention may be utilized as an alternative to a typical arteriovenous(hereinafter “AV”) fistula, AV graft, or large central venous catheterused during modern kidney dialysis procedures. These ports are designedto raise the comfort level of a dialysis patient and to reduce the riskof access damage while also reducing the effort of the medical staffrequired to conduct the dialysis.

Unfortunately, a significant number of individuals suffer from decreasedkidney function. If the kidney function is depreciated enough, usuallyto approximately 10% of normal levels, an individual must either undergokidney dialysis procedures or receive a kidney transplant. Dialysisprocedures remove toxic substances, waste, and bodily fluids from thebloodstream when the kidneys are unable to do so. Presently, two typesof dialysis are commonly utilized, peritoneal dialysis and hemodialysis.

Peritoneal dialysis generally involves injecting special solutions intothe abdomen of a patient through a port, or plastic tube. The specialsolution enters the abdomen and occupies the space around the abdominalorgans known as the peritoneal cavity. Wastes, toxins, and excess bodilyfluids mix with the special solution and are retained therein throughosmosis. Once the special solution absorbs a sufficient amount of thewastes, toxins, and excess fluids, the combination may be drained outthrough the port. This process can either occur every four to six hoursin a manual procedure, or continuously if used in conjunction with acycler machine. While this procedure may usually be performed at home bythe patient it will be appreciated that such a process creates a greatburden on the patient, and typically interferes with normal lifefunctioning.

Hemodialysis is conducted by circulating blood through an externalfiltering machine. Typically, a patient will require hemodialysisthree-times per week, with each session lasting approximately fourhours.

In hemodialysis, an “arterial” catheter removes blood from the body. Theblood is then pumped across a semi-permeable membrane containingsolutions to remove toxins, wastes, and excess bodily fluids. Thecleansed blood is then returned to the body through a “venous” catheter.Other than in emergency situations, dialysis access is generallyobtained through an AV fistula or AV graft. The same graft serves toboth supply blood to the hemodialysis machine as well as return blood tothe body. In this regard, two catheters are typically placed into the AVfistula or AV graft. The catheter closest to the heart typically servesas the “arterial” catheter, flowing blood from the body, and thedownstream catheter typically serves as the “venous” catheter, returningblood to the body. Because the pressure gradient between the two needlesis typically not great, the hemodialysis machine must include a pump tocirculate the blood.

Because, peripheral veins are typically too small in diameter to permitthe required flow of 250 milliliters of blood per minute back into thebody, AV fistulas are surgically created approximately six weeks beforehemodialysis begins in order to artificially enlarge a vein. This isdone by joining a vein to an artery in a localized area while thepatient is under anesthesia. The increased blood from the artery causesthe vein to enlarge and thicken, thus permitting larger flows throughthe vein then would otherwise be possible. After the six weeks that thefistula needs to heal, two dialysis needles may be placed within theenlarged and thickened vein. One needle permits blood to be removed fordialysis and the other permits cleansed blood to return to the enlargedand thickened vein.

For individuals whose veins are not suitable for an AV fistula, an AVgraft may be used. This procedure involves surgically grafting a portionof the patient's saphenous vein, a donor animal artery, or a syntheticconduit and using it to connect an artery to an existing vein. Thegrafted vein or prosthetic conduit may be double punctured to draw bloodinto the dialysis machine and return cleansed blood into the body.

Neither AV fistulas nor AV grafts are ideal. The resulting increasedblood through the veins may cause a neo-intimal hyperplasia which couldocclude the veins and lead to access loss. Additionally, the direct flowof blood from an artery into the veins puts undue strain on the localvascular system in general, and the heart in particular. Finally,because blood is both withdrawn from and returned to the body in thesame AV fistula, dialysis is typically inefficient because of thephenomenon of recirculation.

Recent dialysis advances involve the implanting of dialysis access portsbeneath the skin. These ports generally contain a chamber plugged with aself-sealing material, such as rubberized silicone, with a syntheticcatheter extending out from within the chamber. The port is placed underthe skin and the catheter is surgically implanted into a vein. A secondport is similarly implanted beneath the skin and its catheter issurgically implanted into another portion of the vein. One port may thenbe used to remove blood for dialysis while the other port is used toreturn the cleansed blood back to the body.

Ports constructed in this manner tend to clot when not in use—especiallyfrom the port from which blood is being drawn. Also, because bothcatheters are inserted into the same vein, portions of the cleansedblood that has been returned to the body may be recycled back into thedialysis machine, making the procedure inefficient. As such,improvements have been contemplated.

One such improvement involves the implantation of a single portcontaining three recesses, each enclosed by self-sealing material. Twoof the recesses are generally larger than the third. The larger tworecesses include catheters extending from their reservoir to a veinwithin the body, typically the superior vena cava. The two largerrecesses act in a substantially similar manner as the two separate portspreviously described to remove blood for dialysis and replenish it tothe body. The third recess includes two channels extending into the twolarger recesses. An anti-clotting agent, such as heparin, may bedeposited into the third recess where it is drawn off into the other tworecesses. This helps to prevent the larger two recesses and associatedcatheters from clotting.

Although these devices represent improvements over the previous dialysistechniques, there remains a need for further improvement.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the invention, there is disclosedan implantable access port comprising a hollow port casing having afirst channel, a second channel and a third channel. A self-sealinginsert may be disposed within the third channel. The implantable accessport may further comprise a graft having a first branch, a secondbranch, and a third branch, the first branch extending from the firstchannel and adapted to be anastomosed to a first vessel at a firstlocation, the second branch extending from the second channel andadapted to be anastomosed to a second vessel in a second location, thethird branch extending at least partially into the third channel,wherein the third branch is disposed between the self-sealing insert andthe hollow port casing.

In another embodiment, an implantable access port may comprise a hollowarterial port casing having a first arterial channel, a second arterialchannel and a third arterial channel. A self-sealing arterial insert maybe disposed within the third arterial channel. The implantable accessport may further comprise an arterial graft having a first arterialbranch, a second arterial branch, and a third arterial branch, the firstarterial branch extending from the first arterial channel and adapted tobe anastomosed to an artery at a first arterial location, the secondarterial branch extending from the second arterial channel and adaptedto be anastomosed to an artery in a second arterial location, the thirdarterial branch extending at least partially into the third arterialchannel, wherein the third arterial branch is disposed between theself-sealing arterial insert and the arterial hollow port casing. Theimplantable access port may further comprise a hollow venous port casinghaving a first venous channel and a second venous channel. Aself-sealing venous insert may be disposed within the second venouschannel. The implantable access port may further comprise a venous grafthaving a first venous graft end in fluid communication with the firstvenous channel and a second venous graft end adapted to be anastomosedto a vein. The arterial hollow port casing and the venous hollow portcasing may be connected to each other.

In accordance with one method of performing a medical procedure of thepresent invention, a first catheter may be inserted into a hollowarterial port casing implanted subcutaneously in a mammal such thatblood flows continuously through portions of the hollow port casing andthe first catheter is in fluid communication with the blood. The methodmay further comprise filtering the blood withdrawn from the firstcatheter and recycling the blood to a second catheter.

In another embodiment of the present invention, an implantable accessport may comprise a port casing having a graft with first and secondends extending therethrough and a channel extending from within thegraft to an exterior surface of the port casing. A self-sealing insertmay be disposed within the channel to seal against the flow of fluid.The first end of the graft may be adapted to be anastomosed to a vesselin a first location and the second end of the graft may be adapted to beanastomosed to the vessel in a second location.

In yet another embodiment of the present invention, an implantableaccess port may comprise a port casing having a first channel extendingtherethrough and a second channel extending from the first channel to anexterior surface of the port casing. The implantable access port mayfurther comprise a graft having a first end and a second end, the graftdisposed within the first channel of the port casing such that the firstend and the second end are exterior to the port casing. A self-sealinginsert adapted to prevent fluid from passing may be disposed within thesecond channel. The first end and the second end of the graft may beadapted to be anastomosed to an artery such that blood will continuouslyflow through the port casing.

In still another embodiment of the present invention, an implantableaccess port may comprise first and second port halves capable of beingconnected to each other and a port core adapted to be disposed betweenthe first and second port halves when the first and second port halvesare connected to each other. The first and second port halves each maycomprise a first recess channel and a second recess channel, wherein thefirst recess channel of the first port half and the first recess channelof the second port half generally form a shaped opening when the firstand second port halves are connected to each other and the second recesschannel of the first port half and the second recess channel of thesecond port half generally form a chamber in which the port core isdisposed when the first and second port halves are connected to eachother. The port core may further comprise an upper section having anaperture filled with a self-sealing insert and a lower section having anaperture with a graft disposed therethrough, the graft may extend fromwithin the shaped opening when the first and second port halves areconnected to each other.

In another method of implanting an implantable access port of thepresent invention, the method may comprise severing an artery such thatthe artery comprises a first end and a second end. Anastomosing a graftto the first end and the second end of the artery such that blood mayflow continuously through the graft, wherein the graft is a component ofa port core comprising an upper portion having an aperture extendinginto the graft, the aperture being partially filled with a self-sealinginsert. The method may further comprise connecting a first port half anda second port half around the port core to form the complete implantableport.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with features, objects, and advantages thereof may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 is a diagrammatic view of a hemodialysis system utilizing oneembodiment of the implantable access port of the present invention;

FIG. 1 a is a partial blow-up view of the hemodialysis system utilizingone embodiment of the implantable access port of the present inventionshown in FIG. 1;

FIG. 2 is a perspective view of an implantable access port in accordancewith one embodiment of the present invention shown attached to an arteryand a vein;

FIG. 3 is a cross-sectional view of the implantable access port of FIG.2 taken along section lines A—A;

FIG. 4 is a cross-sectional view of the implantable access port of FIG.2 taken along section lines B—B;

FIG. 5 is cross-sectional view of an implantable access port inaccordance with another embodiment of the present invention;

FIG. 6 is a perspective view of an implantable access port in accordancewith yet another embodiment of the present invention shown in anunassembled position;

FIG. 7 is a perspective view of the implantable access port of FIG. 6shown in a partially assembled position;

FIG. 8 is an exploded view of another embodiment of the implantableaccess port of the present invention; and,

FIGS. 9 a–d are perspective views depicting one method of installing animplantable access port constructed in accordance with anotherembodiment of the present invention.

DETAILED DESCRIPTION

In the following is described the embodiments of the implantabledialysis access port of the present invention. In describing theembodiments illustrated in the drawings, specific terminology will beused for the sake of clarity. However, the invention is not intended tobe limited to the specific terms so selected, and it is to be understoodthat each specific term includes all technical equivalents that operatein a similar manner to accomplish a similar purpose.

Referring to the figures, FIG. 1 depicts a diagrammatic view of atypical hemodialysis system utilizing one embodiment of the implantabledialysis access port 2 of the present invention. As shown in FIG. 1, theimplantable dialysis port 2 may be implanted into the chest area 100 ofthe human body. The implantable dialysis port 2 may also be implantedinto other areas of the body, so long as it is implanted in reasonableproximity to a medium sized artery, typically between 6 and 8 mm, foruse with the implantable dialysis port 2. As will be discussed, theimplantable dialysis port preferably comprises an arterial port 4 and avenous port 6 connected to each other in a single structure. In otherembodiments, the ports 4, 6 may be separate structures which may includefeatures to permit their attachment to each other.

As shown more particularly in FIG. 1 a, an arterial graft 12 generallyextends through the arterial port 4 while a venous graft 18 extends fromthe venous port 6. During the implantation process, the arterial graft12 is preferably connected at each of its ends to the sidewall of anartery 26 while the end of the venous graft 18 is connected to a vein34. In other embodiments, the arterial graft 12 may be connected to theartery 26 by a pair of end-to-end anasomoses. Additionally, the venousgraft 18 may take the form of a venous catheter which is inserted intothe vein 34 such that it may enter the central venous system.

As will be discussed in greater detail below, dialysis may be conductedby tapping the arterial port 4 with an arterial catheter 102 and thevenous port with a venous catheter 104. Each of the arterial and venouscatheters 102, 104 are connected to a dialysis machine 106 comprising apump 108 and a membrane 110. Blood is permitted to flow from the artery26 into the arterial port 4 and through the arterial catheter 102 intothe membrane 110 of the dialysis machine 106 for cleansing. The pump 108then drives the blood through the venous catheter 104 and the venousport 6 into the vein 34. Other than the use of the implantable dialysisport of the present invention, this dialysis technique is similar tothat presently utilized in the art. In addition, it will be appreciatedthat dialysis machines 106 may have pumps 108 in series prior to themembrane 110, rather than after as previously discussed. Because of thepressure gradient between the arterial and venous systems inherent in amammal, it may also be possible that no pump 108 is required as thepatient's heart may be sufficient to circulate blood through thedialysis machine 106 as well as the patient's body.

FIG. 2 depicts a perspective view of an implantable dialysis access port2 as it is intended to be installed in the human body in accordance withthe first embodiment of the present invention. As previously discussed,the implantable dialysis access port 2 preferably comprises an arterialport 4 and a venous port 6 connected to each other or formed together.The arterial port 4 includes an arterial port casing 8 having an opening10 through its upper surface 11. An arterial graft 12 extends throughthe arterial port casing 8. The venous port 6 includes a venous portcasing 14 having an opening 16 through its upper surface 17. A venousgraft 18 extends from the venous port casing 14.

The arterial graft 12 comprises a first end 20, a second end 22 andmidsection (not shown). The first end 20 and second end 22 are eachexterior to the arterial port 4 while the midsection (not shown) isdisposed within the arterial port casing 8 and in direct fluidcommunication with opening 10. The first end 20 of the arterial graft 12may be grafted to a medium-sized artery 26 within the human body. Thisgraft is conducted in a surgical procedure and is typically an end toside anastomosis. Procedures of this type are well known in the art.Similarly, second end 22 of arterial graft 12 may be grafted to a secondportion of artery 26. This graft is also an end to side anastomosis.

By grafting the arterial graft 12 to artery 26 in such a manner, abypass of the artery through the arterial graft is created. Blood istherefore permitted to flow simultaneously through artery 26 andarterial graft 12. The blood flowing through arterial graft 12 will alsoflow through arterial port casing 8 through the open midsection ofarterial graft 12. A self-sealing insert 28, such as a rubberizedsilicone insert or the like, inserted within the opening 10 of arterialport casing 8 prevents this blood from flowing out through the opening10 of arterial port casing 8.

When arterial port 4 is not being used for actual dialysis procedures,blood will continuously flow through arterial graft 12 in a parallelsystem to that of the blood flowing through artery 26, and will thencontinue to flow throughout the remainder of the body. Because none ofthe blood within arterial graft 12 is permitted to remain stagnant, noclotting should occur.

If preferred, the two grafts may also be conducted in end-to-endanastomosis. In either event, blood will be permitted to continuouslyflow through the arterial graft 12, so as to help eliminate clottingtherein.

As previously stated, the implantable dialysis port 2 of the firstembodiment also includes a venous port 6 connected to the arterial port4. Venous graft 18, extending from venous port 6, comprises a first end30 and a second end 32. The first end 30 is attached to the venous portcasing 14 and is in direct fluid communication with opening 16. Thesecond end 32 is typically grafted to a vein 34 within the human body inan end to side anastomosis. Connection of the venous graft 18 may alsobe conducted by a large bore cannulation of a central vein, if sodesired. In addition, the venous graft 18 may take the form of a venouscatheter and may be inserted directly into a vein 34 so its end 32 mayextend into the central venous system. Although continued reference maybe made to venous grafts 18 throughout this text, it is to be understoodthat such references may also be interpreted as allowing for the use ofvenous catheters as well. Each of these types of connections are wellknown in the art.

As with arterial port casing 8, venous port casing 14 also contains aself-sealing insert 36 within its opening 16. This self-sealing insert36 prevents blood from flowing through opening 16 of venous port casing14. Once venous graft 18 is anastmosed to vein 34, blood may freely flowfrom vein 34 through venous graft 18. Because venous graft 18 isconstructed in a “dead end” relationship with venous port 6, blood mayremain stagnant within the venous port 6 and venous graft 18 once thedialysis procedure is completed and the venous port 6 is sealed. It willbe appreciated that the likelihood of blood being recycled back to vein34 from first end 30 of venous graft 18 is inversely proportional to thelength of the venous graft.

It is well known in the art that stagnant blood may clot. To avoid therisk of clotting, the entire track from venous port 6 through venousgraft 18 is preferably flushed with a saline solution. A pre-meteredvolume, approximately equal to the volume of the venous graft 18, ofheparin or other anti-clotting agent may then be injected into thevenous graft. Thus, blood is completely displaced from the venous port6, opening 16 and venous graft 18 and is replaced with the anti-clottingagent. Upon start-up of the next dialysis procedure, the anti-clottingagent is permitted to flow from the body through the venous port 6 untilfresh blood appears. The venous catheter 104 may then be connected tothe dialysis machine 106 for initiation of the dialysis procedure.Similar procedures are well known in the medical industry. Because ofthe limited life-span of the self-sealing insert 36, it is preferredthat a single needle be utilized to withdraw the blood, flush the line,and fill the line with heparin.

As shown in FIG. 2, the flow of blood through the arterial port 4 willgenerally be in the direction of arrows A, away from the heart, whilethe flow of blood through venous port 6 will generally be in thedirection of arrows B, toward the heart.

FIG. 3 illustrates a cross section of the implantable dialysis accessport 2 of FIG. 1, taken along section line A—A of FIG. 1. As can beseen, the arterial port 4 and venous port 6 of the implantable dialysisaccess port 2 may be constructed monolithically, so to form an integralunit. As will be described hereinafter, the arterial port 4 and thevenous port 6 may also be constructed separately. If so constructed,they may remain separate when placed in the body, or may be adaptablesuch that they can be connected to form one unit.

The arterial and venous port casings 8, 14 are generally constructed ofa dense material such as plastic, stainless steel, or titanium, so as tobe impenetrable by a needle. The material must also be compatible withimplantation within the human body. The shape of the port casings 8, 14must also be compatible with implantation into the human body.Accordingly, there preferably are no sharp edges.

The arterial and venous grafts 12, 18 must also be constructed ofbiocompatible material. As well known in the industry, such grafts maybe formed from expanded polytetrafluroethylene (PTFE), teflon orpolyester.

As may also be seen in FIG. 3, the opening 10 of arterial port casing 8preferably comprises a plurality of indented regions 38, or othersurface irregularities, into which the self-sealing insert 28 may fit.The indented regions 38 assist to prevent the self-sealing insert 28from being pulled from the arterial port casing 8 upon removal of aneedle or being pushed into arterial graft 12 upon insertion of aneedle, or otherwise becoming dislodged.

Venous port casing 14 of venous port 6 is constructed in much the samemanner as arterial port casing 8 of arterial port 4. In this regard,port casing 6 may include a plurality of indented regions 40 for thepurpose of securing self-sealing insert 36 there within.

FIG. 4 depicts a more detailed cross sectional view of arterial port 4in accordance with the first embodiment of the present invention takenalong section line B—B of FIG. 1. In this view, it can be clearly seenthat arterial graft 12 contains a branch portion 13 extending intoopening 10 of arterial port casing 8. The branch portion 13 of arterialgraft 12 is either formed integrally with arterial graft 12 during themanufacturing process, or is grafted on in an end to side anastomosisprior to being installed into opening 10. Preferably, the branch portion13 extends beyond at least one of the indented regions 38. Whenextending so, self-sealing membrane 28 will preferably providesufficient pressure to secure branch portion 13 in place. Biocompatibleadhesives may also be applied between the branch portion 13 of arterialgraft 12 and the arterial port casing 8 to assist with securing of thebranch portion 8 to the arterial port casing.

Casing 17, preferably formed of metal or other puncture resistantmaterial, may also be included between the self-sealing insert 28 andthe branch portion 13 of arterial graft 12. The casing 17 may beprovided to help prevent penetration, tearing, or other damage of thebranch portion 13 of arterial graft 12 by the needle used duringhemodialysis.

Referring back to FIG. 3, the venous graft 18 may be connected to thevenous port 6 in a different manner. In a preferred embodiment, venousport casing 14 includes a spout 52 having a diameter slightly smallerthan that of venous graft 18. Venous graft 18 is fitted over the entirespout 52 to form a shoulder area 54. The shoulder area 54 is then heldin place by a compression ring 56, or other type of pressure fitting.The compression ring 56 may be a simple rubberized O-ring or may be amore elaborate fixture, such as a stainless steel clamp. Either way, thepressure fitting should be sufficient to prevent the ingress or egressof fluids past the connection. The fitting should also be of sufficientstrength to completely secure the venous graft 18 to the spout 52.

Referring back to FIG. 4, it will be appreciated that portions ofarterial port casing 8 fall below arterial graft 12 in this embodimentof the invention. One purpose of having arterial port casing 8completely surround arterial graft 12 is to prevent a needle frompiercing through the lower portion 15 of arterial graft 12 when theimplantable dialysis port 2 is in use. The lower portion also preventsthe arterial graft 12 from collapsing when a needle is inserted into theself-sealing membrane 28. Preferably, any such needle will be calibratedso that it is not long enough to puncture the arterial graft 12, but islong enough to enter the graft and come in contact with the bloodflowing therein.

As shown in FIG. 2, arterial port casing 8 and venous port casing 14 areeach shown with securing members 44. Each of these securing members 44extend from the respective arterial or venous port casing 8, 14 andforms an aperture 46 there within. One purpose of the securing member 44is to permit a surgeon to secure the implantable dialysis access port 2within the body of the patient. Such securing may be conducted bysuturing or stapling the securing member to tissue within the patient'sbody. Preferably, at least two such securing members are provided perarterial or venous port casings 8, 14. This allows for a total of fourtie-down points to secure the implantable dialysis port 2 in position,which is typically sufficient to prevent detachment.

FIG. 5 depicts a cross-sectional view of an arterial port casing 4′formed independent of the venous port casing (not shown). This portcasing 4′ is otherwise constructed similarly to the port casingspreviously discussed, complete with self-sealing insert 28′, indentedregions 38′, branch portion 13′, casing 17′, and arterial graft 12′. Aswill be shown, arterial port casings 4′ of this type may be accompaniedby separate venous port casings 6′.

FIG. 6 depicts an implantable dialysis access port 2′ in accordance witha further embodiment of the present invention. Like the embodiment shownin FIG. 5, in this embodiment the arterial port 4′ and venous port 6′are constructed as two separate elements. Each port 4′, 6′ includes aplurality of elongate protruding ribs 50 and a plurality of elongatereceiving ribs 48. Each of the protruding ribs 50 may flare outward fromthe respective port 4′, 6′ to form bulbous extending portions 52. In themeantime, each of the receiving ribs 48 may extend inward of the port4′, 6′ to form bulbous receiving portions 54 sized and shaped inregistration with the bulbous extending portions 52.

Preferably, one port 4′, 6′ includes receiving ribs 48 and protrudingribs 50 alternating around its entire exterior surface while the otherport 4′, 6′ includes such alternating ribs only along a single side,which preferably has a shape corresponding to that of the other element.For example, in the embodiment shown in FIG. 6, the arterial port casing8′ of arterial port 4′ includes ribs 48, 50 around its entire exteriorsurface while venous port casing 14′ of venous port 6′ includes suchalternating ribs 48, 50 only along a single side, which has an arcuatesurface corresponding to the rounded surface of arterial port 4.

The receiving ribs 48 of venous port 6′ are in registration with theprotruding ribs 50 of arterial port 4′ and the protruding ribs 50 ofvenous port 6′ are in registration with the receiving ribs 48 ofarterial port 4′ to facilitate engagement of the two structures. Ifarterial port 4′ is provided with receiving ribs 48 and protruding ribs50 around its entire exterior surface, it will be appreciated thatvenous port 6′ may then be engaged with arterial port 4′ in a number ofaxes of rotation. Such an arrangement is preferential as it permits asurgeon to strategically place the venous port 6′ in relation to thearterial port 4′ in accordance with the particularities of theindividual into which the implantable dialysis access port 2′ is to beimplanted.

As shown in FIG. 7, in order to connect to arterial port 4′ to thevenous port 6′, the two ports should be aligned such that the protrudingribs 50 of the venous port 6′ align with the receiving ribs 48 ofarterial port 4′. Once aligned, the venous port 6′ may be slid relativeto the arterial port 4′ to engage the two to each other. It will beappreciated that the bulbous protruding portion 52 will completely fillthe bulbous receiving portion 54 of the respective receiving rib 48.

It is also a feature of this invention that the arterial port 4′ and thevenous port 6′ may be implanted in different areas of the patient. Forexample, one port 4′, 6′ may be implanted in the left shoulder areawhile the other port 4′, 6′ is implanted in the right shoulder area.This will not alter the efficiency of dialysis. Rather, the ports 4′, 6′may be implanted in this manner to achieve greater patient comfort.There is no requirement that the ports 4′, 6′ be in connected to eachother, or even in proximity to each other.

It will be appreciated that the ports 4′, 6′ shown in FIGS. 6 and 7include an arterial graft (not shown) and a venous graft (not shown),respectively. Neither of these grafts has been shown in FIGS. 6 and 7for clarity. Notwithstanding, each may be provided in accordance withthe techniques previously discussed with respect to the various otherembodiments of the present invention.

FIG. 8 depicts a perspective view of yet another embodiment of thepresent invention. In this embodiment, the arterial port 4″ is providedin three parts, a first arterial port half 200, a second arterial porthalf 202, and an arterial port core 204.

The first arterial port half 200 and the second arterial port half 202may be combined to form a complete outer shell of the arterial port 41″.Each arterial port half 200, 202 comprises an arcuate portion 206forming a shaped opening, such as a complete cylinder when combined.Each arterial port half 200, 202 also comprises a second arcuate portion208 forming a chamber generally running perpendicular to the completecylinder. The chamber and the complete cylinder are in fluidcommunication with each other, and overlap in portions of each.

The arterial port core 204 comprises a graft 210 extending through acylindrical lower casing 212. The graft 210 may be secured to thecylindrical lower casing 212 with a biocompatible adhesive ormechanically. Mounted upon the cylindrical lower casing 212, or formedintegrally therewith, may be a cone-shaped upper section 214. Thecone-shaped upper section may be filled with a self-sealing insert 216,supported therein by surface irregularities or biocompatible adhesives,as in other embodiments of the present invention.

In other embodiments of the invention, one half of arterial port core204 may include a venous port coupled to its exterior surface, or mayotherwise be adapted to accept a venous port being coupled to itsexterior surface.

As shown in FIGS. 9 a through 9 d, the arterial port 411 may beimplanted into the body of a mammal. To achieve such implantation, anartery, such as artery 26 shown in FIG. 9 a, may be severed in two toform a first artery end 218 and a second artery end 220, as shown inFIG. 9 b. Preferably, the artery 26 is at least a medium sized artery ofapproximately 6 to 8 mm in diameter. As shown in FIG. 9 c, the graft 210of the arterial port core 204 may be anastamosed to the first artery end218 and the second artery end 220 such that it is interposedtherebetween to permit blood to flow from the first artery end 218 tothe graft 210 and then through the second artery end 220, or vice-versa.Because the entire port is not installed in this step, the gap in theartery may be as little as approximately 2 cm, rather than theapproximately 6 cm that would be required if the entire port wereimplanted at this time. The first arterial port half 200 and the secondarterial port half 202 may then be placed around the combination suchthat the arcuate portions 206 surround the graft 210 and the secondarcuate portions 208 surround the cylindrical lower casing 212 and thecone-shaped upper section 214. As shown in FIG. 9 d, the fist arterialport half 200 may then be snapped together with the second arterial porthalf 202 to form the complete arterial port 4″.

It will be appreciated that methods of connecting the two port halves200, 202 to each other are well known in the industry and include snapclosures, as well as other mechanical fixation methods such as nuts andbolts, screws, biocompatible adhesives, and the like. If mechanicaldevices are utilized, they may be coated after installation with abiologic glue or silicone to prevent tissue growth. It will beappreciated that once complete, the arterial port 4″ may be used in thesame manner and for the same procedures as described with regard toother aspects of the present invention, including hemodialysis throughpuncturing of the semi-permeable membrane 216.

The arterial port 4″ is preferably of a sufficient length to completelycover and protect the anastomosis between the graft and the artery ateach location.

As previously discussed, implantation techniques suitable for implantingthe implantable dialysis access ports 2 in accordance with certainembodiments of the present invention are well known in the medical arts.The implantable dialysis access port 2 is typically implantedsubcutaneously in the shoulder area below the clavicle, although it mayalso be implanted elsewhere in the body. It is placed such that theself-sealing insert 28 of arterial port 4 and self-sealing insert 36 ofvenous port 6 face outward from the chest, just below the surface of theskin. Preferably, these ports 4, 6 are located at slightly differentelevations, as shown in FIG. 1, or are constructed of differentgeometries, such as shown in FIGS. 6 and 7 where the arterial port 4′includes a domed head 56 and the venous port includes a flat uppersurface 58. The purpose of providing a distinction between the two ports4, 6 is so that a dialysis technician, or other medical personnel, mayidentify each port 4, 6 during the dialysis procedure by applying slightpressure to the skin with her fingers to discern the elevation and/orshape. As previously discussed, the arterial port 4 should be hooked upto the input of the dialysis machine and the venous port 6 hooked up tothe output to take advantage of the pumping power of the patient'sheart.

Referring back to the embodiment shown in FIG. 2, after implantation ofthe ports 4, 6, the first end 20 and second end 22 of arterial graft 12may be grafted to artery 26. Techniques for such end to side grafts arewell known in the industry and may be employed. It will also beappreciated that end-to-end anastomosis may also be utilized. Once thegrafts are in place, blood will be permitted to flow through arterialgraft 12 which is in direct fluid communication with opening 10.However, blood is prevented from escaping from arterial port casing 8 bythe placement of self-sealing insert 28. Similarly, venous graft 18 maybe grafted upon vein 34 to permit blood to flow from vein 34 throughvenous graft 18 which is in direct fluid communication with opening 16.Blood is prevented from flowing past arterial port casing 8 by virtue ofthe placement of self-sealing insert 36. Once the arterial graft 12 andvenous graft 18 are in place, the implantable dialysis access port maybe sutured or stapled into its final placement utilizing securingmembers 44, as previously discussed. The patient's skin may then besutured and the patient permitted to heal.

As best shown in FIG. 4, self-sealing insert 28, conforms to theinternal shape of the port casing within which it is placed, in thiscase arterial port casing 8. The self-sealing insert, 28 is typicallyformed from rubberized silicone. Other materials may also be used, solong as the material is sufficiently elastic so as to seal against theback pressure of the blood when the implantable dialysis port 2 is notbeing used for dialysis, so long as it is compatible with placementinside the human body, and so long as it will self-seal upon removal ofa needle, among other required qualities. Preferably, the self-sealinginsert 28 will be able to remain self-sealing through a lengthy lifespanand numerous needle punctures.

Dialysis on a patient who has the implantable dialysis access port 2previously installed is intended to be relatively simple and nearly painfree. On the patient's scheduled dialysis day, either the patient or atechnician locates the implantable dialysis access port 2 just below thesurface of the patient's skin. Because the arterial port 4 and venousport 6 are on different elevations, are shaped differently or are atdifferent locations in the body, they can be distinguished from oneanother easily. Once they are located and distinguished, the patient ortechnician must pierce the patient's skin and self-sealing membrane 28of the arterial port 4 with a needle and arterial catheter assembly 102to permit uncleansed blood from the body to flow into the dialysismachine 106. Similarly, the patient or technician must pierce thepatient's skin and the self-sealing membrane 36 of the venous port 6with a needle and venous catheter assembly 104 to enable cleansed bloodfrom the dialysis machine 106 to be returned to the body. Such piercingmay initially be conducted with the aid of a local anesthetic toalleviate any pain the patient may endure. However, after severaliterations of the process, a desensitized callous should form which maythen be pierced such that no local anesthesia will be required uponsubsequent punctures.

It will be appreciated that the needle used for this technical procedureis preferably a side port non-coring type needle. This type of needleallows blood to either enter or exit the needle from the side of theneedle, but will not cause extensive damage to the self-sealing insert28, such as would be caused by a coring type needle.

Following the dialysis procedure, the arterial catheter 102 transferringblood from the body to the dialysis machine 106 may be removed. Thevenous catheter 204 transferring blood from the dialysis machine 106 tothe body may be separated from the needle puncturing the self-sealinginsert 36 of the venous port 6. The venous port 6 may then be flushedwith a saline solution. Finally, a metered amount of anti-clottingagent, such as heparin, may be injected. The heparin injected should besufficient to displace all of the blood from within the venous port 6and venous graft 18. The heparin should be sufficient to preventclotting of blood within these areas between dialysis sessions.

Typically, each of the elements of the implantable dialysis port 2 willlast for the lifetime of the patient. Thus, the implantable dialysisport 2 may remain in a single implanted location. Nevertheless, if oneelement fails, it will typically be one of the grafts 12, 18. Even if agraft 12, 18 fails, the implantable dialysis port 2 may remain in thesame location after the graft is surgically repaired, using conventionalmethods known in the medical arts.

As stated, the invention provides an arterial port 4 in direct fluidcommunication with an artery 26 and a venous port 6 in direct fluidcommunication with a vein 34. This permits the invention to be veryefficient, as blood is drawn off and returned to different systemswithin the body. In addition, it permits use of dialysis machines withless powerful pumps, as much of the energy required to pump the blood isprovided by the heart. In fact, for some individuals, a pump will not berequired as the natural pressure gradient between the arterial andvenous systems may be sufficient to drive the blood through the completesystem. Because an external pump may not be required, the heart may notbe subjected to an increased pressure output.

Additionally, because blood from the venous and arterial systems is usedthere is no risk of ischemia due to esteal syndrome, as with methods ofthe prior art. There is also no risk of destruction of the local venoussystem.

In addition to use of the self-sealing inserts such as self-sealinginsert 28, it will be appreciated that various mechanical valves mayalso be utilized. Such valves should serve the purpose of preventingunwanted blood flow from within the port 4, 6, while permittingselective entry of a catheter device for blood input or output. Suchvalves should also be provided with self-sealing abilities.

It will also be appreciated that a single implantable dialysis port,configured with a “pass through” type graft such as arterial access port4, may have uses other than for dialysis. Such uses include situationswhere patients require frequent vascular injections or infusions oftherapeutic fluids. Other uses include situations where a patient mayrequire constant monitoring of blood gases or frequent drawing of blood,such as patients relying on in-home cardiac support systems. In suchcases, the single port may be implanted and utilized to assist with theprocedures.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. An implantable access port comprising: a port casing having a firstchannel extending therethrough and a second channel extending from saidfirst channel to an exterior surface of said port casing; a graft havinga first end and a second end, said graft disposed within said firstchannel of said port casing such that said first end and said second endare exterior to said port casing, said graft having a third end disposedwithin said second channel; a self-sealing insert adapted to preventfluid from passing disposed within said second channel such that saidthird end of said graft is between said self-sealing insert and saidport casing; wherein said first end and said second end of said graftare adapted to be anastomosed to a blood-carrying vessel such that bloodwill continuously flow through said port casing.
 2. The implantableaccess port of claim 1, wherein said self-sealing insert is adapted tobe penetrated by a needle and catheter system to transfer fluids into orout of the artery through said port casing.
 3. The implantable accessport of claim 2, wherein said transfer of fluids is the removal of bloodfrom within the artery.
 4. An implantable access port comprising: firstand second port halves capable of being connected to each other and aport core adapted to be disposed between said first and second porthalves when said first and second port halves are connected to eachother; said first and second port halves each comprising a first recesschannel and a second recess channel, wherein said first recess channelof said first port half and said first recess channel of said secondport half generally form a shaped opening when said first and secondport halves are connected to each other and said second recess channelof said first port half and said second recess channel of said secondport half generally form a chamber in which said port core is disposedwhen said first and second port halves are connected to each other; saidport core comprising an upper section having an aperture filled with aself-sealing insert and a lower section having an aperture with a graftdisposed therethrough, said graft extending from within said shapedopening when said first and second port halves are connected to eachother.
 5. The implantable dialysis port of claim 4, wherein said graftfurther comprises a first end adapted to be anastomosed to a firstvessel and a second end adapted to be anastomosed to a second vessel. 6.The implantable dialysis port of claim 5, wherein said first and secondvessel are an artery of a mammal.
 7. An implantable access portcomprising: a port core having an upper section and a lower section,said upper section having an upper section channel extendingtherethrough, said lower section having a lower section channelextending therethrough, said upper section channel and said lowersection channel in fluid communication; a self-sealing insert disposedwithin said upper section channel; a graft extending through said lowersection; a first port half and a second port half, said port halvesadapted to be brought together to at least partially surround said portcore.
 8. The implantable access port of claim 7, wherein portion of saidgraft also extends into said upper section channel.
 9. The implantableaccess port of claim 8, wherein said self-sealing insert is deposed atleast partially within said portion of said graft extending into saidupper section channel.
 10. The implantable access port of claim 8,wherein at least one of said port core and said outer casing is adaptedto prevent a needle from piercing said graft.
 11. The implantable accessport of claim 10, further comprising an insert within said upper sectionchannel between said portion of said graft extending into said uppersection channel and said self-sealing insert, said insert beingimpenetrable by a needle so as to protect said graft from damage. 12.The implantable access port of claim 7, wherein said first port halfincludes a securing member to permit securing of the implantable accessport within the body of a patient.
 13. The implantable access port ofclaim 7, wherein the upper section channel includes at least oneindented region.
 14. The implantable access port of claim 13, whereinsaid self-sealing insert is adapted to fit within said at least oneindented region.
 15. The implantable access port of claim 7, wherein theupper section channel includes surface irregularities.
 16. Theimplantable access port of claim 7, wherein said graft is constructed ofone of expanded polytetrafluroethylene, teflon, and polyester.
 17. Theimplantable access port of claim 7, wherein said port halves surroundportions of said graft beyond the limits of said port core.